This invention pertains to padded track rails and more particularly to padded rail plate for use on a tracked vehicle adapted to prevent the pad from ripping away from the track rail during use.
Tracked vehicles include various pieces of heavy machinery including concrete cutters, diggers, ice cutters, paving machinery, cranes, bulldozers and the like. The use of tracks provides improved traction on concrete surfaces and improved stability and flotation on softer surfaces such as dirt. Generally the tractor rails are composed of forged steel. The great weight associated with these vehicles, often more than ten tons, results in great pressure exerted upon a road surface by the track, especially during turning of the vehicle. Track pads have been used to protect road surfaces from damage caused by tracks, as well as to protect the track rails themselves. Track pads also provide improved traction on hard surfaces.
Many resilient track rail pads have been developed and used to cover track rails. However, the high stresses applied to these pads during use has resulted in the recurrent problem of the pads separating and ripping away from the steel mounting rail prior to the pad wearing out. In addition to direct tearing forces applied to a track pad during use horizontal expansion and contraction of the pad which occurs as a result of the vertical deflection of the pad from pressure between the track and the roadway adds to the breaking and tearing of pads from the rail plate.
Attempts have been made to solve the problem of breaking and separating of track pads, see eg. U.S. Pat. No. 3,944,296. This patent discloses a track plate having curved ends about which a resilient pad means is molded. The edges of the resilient pad, however, are not anchored to the plate, nor is a bearing surface provided by the plate to protect the pad from direct tearing forces during use. Thus the problem of breaking of the edges of the pad and consequent tearing of the pad from the rail continues and is not adequately resolved by this design.
Additional attempts to solve the problem of pad breaking and separating have included pads which are easily removeable and replaceable upon the rail plate, see e.g. U.S. Pat. Nos. 2,686,697 (Baker) and 2,869,932 (Eichweber). Replaceable pads require frequent maintenance and constant observation. These pads do not provide a durable long-lasting track pad.
As can be seen from the above discussion, although many attempts have been made, the art has not succeeded in meeting the need for a durable track pad adapted to prevent breaking and ripping from the rail plate.